afm_apsk_mux.vhd

来自「用DE2板子实现的正选信号发生器,需安装quartus2软件,硬件需要DE2的开」· VHDL 代码 · 共 33 行

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.std_logic_arith.all;

entity afm_apsk_mux is
port(sw0,sw1:in std_logic;
     am_out:in std_logic_vector(20 downto 0);
	 fm_out:in std_logic_vector(7 downto 0);
	 ask_out:in std_logic_vector(7 downto 0);
	 psk_out:in std_logic_vector(7 downto 0);
	 q_out:out std_logic_vector(20 downto 0));
end afm_apsk_mux;

architecture rtl of afm_apsk_mux is
signal sel:integer;
signal pad0:std_logic_vector(12 downto 0);

begin
 pad0<="0000000000000";
with sel select 
	q_out<=am_out when 0,
		   pad0&fm_out  when 1,
		   pad0&ask_out when 2,
		   pad0&psk_out when 3,
		  "XXXXXXXXXXXXXXXXXXXXX" when others;
sel<=0 when sw0='0' and sw1='0' else 
     1 when sw0='0' and sw1='1' else 
     2 when sw0='1' and sw1='0' else 
     3 when sw0='1' and sw1='1' else 
     4;

end rtl;